Process for the production of organic compounds containing nitrogen and chlorine combined in an-n=ccl-radical



United States Patent PROCESS FOR THE PRODUCTION'OF ORGANIC COMPOUNDSCONTAINING NITROGEN AND COMBINED IN AN N==CCl- RAD- Hans Holtschmidt andWilfried Zecher, Cologne-Stammheim, Germany, assignors to FarbenfabrikenBayer Akfiengesellschaft, Leverkusen, Germany, a German corporation NoDrawing. Filed Aug. 28, 1962, Ser. No. 220,070 Claims priority,application Germany, Sept. 13, 1961,

F 34,920; Nov. 9, 1961, F 35,319 8 Claims. (Cl. 204-158) The presentinvention relates to a process for the production of organic compoundswhich contain nitrogen and chlorine combined in an -N=CC1 radical, someof which are new compounds.

Our copending patent application Serial No. 220,054, filed August 28,1962, includes a description of a process for the production of organicnitrogen compounds which contain the -N=CClradical which comprises (1)reacting a compound having the formula in which R and R separately standfor an alkyl or aryl group which may be substituted by halogen, cyano,aryl, alkyl, amino or imino groups, and in which R and R together with=N- jointly stand for an isocyclic or heterocyclic ring, and in which Xstands for an acyl group, with chlorine at temperatures below 140 C. tothe extent that all replaceable hydrogen atoms are replaced chlorineatoms, and then (2) treating the chlorination product thus obtained withchlorine at temperatures between 140 C. and 300 C., whereby an acylchloride is split ofl.

It has been found that organic nitrogen compounds which contain the--N=--CClradical can be obtained by first of all reacting .an aminehaving the formula R2 in which R and R separately stand for an alkyl oraryl group which may be substituted by halogen, cyano, aryl, alkyl,amino or imino groups, and in which R and R together with =N- jointlystand for an isocyclic or heterocyclic ring,'and in which R stands for amethyl or an aryl group which can be further substituted, with chlorineat temperatures below 140 C. to the extent that all replaceable hydrogenatoms are replaced by chlorine atoms, and then treating the chlorinationproduct thus obtained with chlorine at temperatures between 140 C. and300 0., whereby an alkyl chloride is split off.

It is important to conduct the reaction with the temperature socontrolled that the amino compounds are so completely saturated withchlorine at temperatures below 140 C. that in the subsequentchlorinating dissociation, which takes place between 140 and 300 C.,condensation and polymerization reactions are prevented. Furthermore,when chlorine is introduced at lower temperatures carbon atoms which arein the alpha position with reference to nitrogen acquire a positivecharge which favors subsequent dissociation rather than any sidereaction.

The amines mentioned are, in general, such strong bases that theirhydrochlorides precipitate at the beginning of 3,251,760- Patented May17, 1966 ice 1,2-bls dimethylamlno ethane H2O .-C H: HzCL JG H: N CH:

N-methylpyrrolidlne C H: i H3O \C Hg N CH:

1,4-d1methylpip erazine (it H20 HzC l N Hac C H251,4-bts(2-ch1'oroethy1) piperazine N-methylpiperidineN,N-dimethylaminoacetonltrile I C H:

l ICHa 01 [Q, l

61 e I 0,115 H1O N C H:

I C 2H -N I /C H: CE: H

z s N hexamethylenetetramine /C H: i 0 Ha C H: 0 Ha 111 I C H3 C H: N02

0 H; I o H; Ga @k g C H: J: C H;

N /C H: (3H3 N ?H3 or .N\ N f I\ N L 0 Ha 4111: N Ly JJH;

C1 N e I H /N -o1 a CH3 g In addition to a substantial. chlorination ofthe whole molecule there may be consequential reactions with which thisinvention is also concerned. Ring structures, for example, N-N'-dimethylpiperazine, are stabilized by a transformation to the aromatic state.Urotropin (hexamethylenetetramine) is split during chlorination in sucha manner that cyanuric chloride is obtained as a reaction product. Inthe case of dimethylamino acetonitrile the cyano radical is split offand the molecule becomes dimeric.

Chlorination can also be carried out in a solvent, especially ifammonium salts with high melting points are used as starting materials.Suitable solvents are, for example, 1,2,4-trichlorobenzene, chloroform,tetrachloroethan and phthalyl chloride. I

.The invention is the more surprising in that direct chlorination ofaliphatic or aliphatic-aromatic amines or of their salts have hithertobeen described in few cases.

It is, for example, known that the addition product of chlorine andtrimethyl amine sometimes dissociates explosively at 35 C. (seeHouben-Weyl, Methoden der organischen Chemie, vol. V/ 3, page 642).

Some of the products obtainable according to the process of the presentinvention are known. The'known compounds are, however, only obtainablewith difiiculty, by other methods. They are valuable products for thepreparation of pest control agents, herbicides, dyestuffs and plastics.Further, they can as such be used as insecticides and nematocides,because of their high activity against spiders, mites, flies and fungi.

As a typical example of the high nematocidal activity of the products ofthe present invention the treatment of infested soil with2,4,6-trichlorophenylimidocarbonyl chloride is shown below.

Soil is heavily infested with the. root cyst nematode Meloidogyneincognita. 25, 5 0, 100 and 200 p.p.m. of2,4,6-trichlorophenyl-imidocarbonyl chloride are added to one liter ofinfested soil. The active agent is applied in admixture with talcum,this mixture containing 1% of active ingredient.

One week after the preparation, seed of soft lettuce was put into thesoil. After a 4 weeks period the plants were checked for cyst formation.The following table shows the effectiveness of the compound inpreventing cyst formation.

.. Percent 25 ppm. 50 ppm. 100 p.p.m. 100 200 ppm. 100

The following examples are given for the purpose of illustrating thepresent invention:

116 parts by weight of. 1,2-bis(dimethylamino)ethane are dissolved in1000 parts by volume of 1,2,4-trichloro benzene. A weak current ofchlorine is then introduced and the strongly exothermic reaction isrestrained by cooling so that the temperature remains between 70-80 C.When the exothermic reaction has subsided, chlorination is continuedwhile the mixture is. irradiated with ultraviolet light, and thetemperature rise is controlled in such a way that within one hour a riseof 1015 C. takes place. a further 3 hours at 200-230 C., then nitrogenis blown through and the solution left to cool. 0n cooling, most of theethylene-1,2-bis-[imidocarbonyl chloride] 'pre'cipitates as crystals,the remainder being obtained by further, evaporating the solution.

The same compound can be obtained by chlorinatin'gdimethyl-amino-acetonitrile with dissociation of cyanogen chloride, bychlorinating under the same conditions as described hercinbefore in thisexample. 'EXAMPLE'Z parts by weight of hexamethylene-tetramine aresuspended in 600 cc. of tetrachloroethane and a gentle stream ofchlorine is passed therethrough at room tem- Subsequently chlorinationis continued for 1 perature, whereby the temperature quickly rises to80-90" C. and the suspension changes to a thick paste. Subsequently thetemperature is slowly raised to 135-140 C. (10 degrees per hour).Chlorination is continued while the mixture is irradiated withultraviolet light until most of the substance has dissolved and there isonly a small residue left. After filtering off the residue thetetrachloroethane is distilled off and the remaining yellow oil isfurther chlorinated at 200-240 C. During chlorination large quantitiesof a white substance of boiling point 190 C. and melting point 146 C.sublime in the condenser. The same substance is obtained by thesubsequent distillation of the chlorination product. The substance wasidentified by analysis, mixed melting point and spectrum as cyanuricchloride.

EXAMPLE 3 355 parts by weight (6 mols) of trimethylamine are dissolvedin 1000 parts by volume of 1,2,4trichlorobenzene while the solution iscooled with ice. Under continued cooling hydrogen chloride is introducedto saturation point. A pasty suspension of the hydrochloride intrichlorobenzene is obtained, into which chlorine is introduced at 140C. for 20 hours while stirring and irradiating the mixture withultraviolet light. The reaction product, a clear dark brown solution, isfractionated in vacuum through a silvered column. The solvent, boilingpoint 90-95 C. at 16 mm. Hg is separated from the other fractions,boiling point 6090 C. at 16 mm. Hg and 95210 C., and a mixture ofchlorinated amines is thus obtained which is chlorinated for 4 hours at170 C. and for 11 hours at 200 C. while the mixture is irradiated withultraviolet light. The product is again fractionated in vacuum through asilvered column. The trichloromethylimidocarbonyl chloride distils overat boiling point 65-67 C. at 17 mm. Hg.

Analysis.C Cl N (molecular weight: 215.3-Calculated:C=11.16%;'Cl=82.35%; N=6.51%. Found: C=11.58, 11.65%; C1=82.1%; N=6.4%,6.7%.

EXAMPLE 4 Chlorine is passed into a suspension-of 576 grams (4 mols) offinely ground -1-dimethylamino-2-chloroethane hydrochloride in 700 cc.of 1,2,4-trichlorobenzene while stirring and irradiating the mixturewith ultraviolet light.

AnaIysis.C Cl N (molecular 'weight: 298.24)-Ca1culated: C, 12.09%;Cl,.83.25%; N, 4.70%. Found: C, 12.61%; Cl 82.55%; N 5.05%.

' culated: c, 22.05%; N, 12.86%.

6 EXAMPLE 5 Trichlorophnylimidocarbonyl chloride 400 grams (2.33 mols)of N-phenyl-N,N,N-trimethylammonium chloride are suspended in 700 cc. of1,2,4- trichlorobenz'ene. The mixture is then chlorinated for 13 hoursat 100 C. while stirring and irradiating it with an ultraviolet lamp.The ammonium salt dissolves and, with liberation of hydrogen chloride, ayellow and a dark brown liquid are obtained which remain separated intwo phases. While continuing the introduction of chlorine thetemperature is raised by 20 C. every two hours until 200 C. has beenreached, when chlorination iscontinued for a further 7 hours at thistemperature. mixture is fractionated in vacuum, the solvent is separatedand the residue chlorinated again at 240 C. for 18 hours. The reactionproduct is then fractionated through a silvered column. Thetrichloro-phenylimidocarbonyl chloride distils over as a faintly yellowliquid with a boiling point of 148153 C. at 15 mm. Hg.

EXAMPLE 6 2,3,5,6-tetrachloro-pyrazine from 1,4-dimethyl-piperazine Asolution of grams (0.7 mol) of 1,4-dimethylpiperazine in 150 cc. ofchloroform is chlorinated, while a cooled with ice, for 8 hours at 30 C.After the reaction, strongly exothermic at the beginning, has subsided,200 cc. of 1,2,4-triehlorobenzene are added, the chloroform is distilledoff and the suspension further chlorinated at higher temperatures,finally'at 200 C. while it is irradiated with ultraviolet light.Distillation under vacuum yields at boiling point -l45 C. and 15 mm. Hga fraction from which 2,3,5,6-tetrachloropyrazine precipitates, oncooling, as colorless crystals. After recrystallization from methanolcolorless flakes of melting point 97-99 C. are obtained.

Analysis.C Cl N (molecular weight: 217.9)calculated: C, 22.05%; Cl,65.09%. Found: C, 22.41%, 22.34%; Cl 64.7%, 65.0%.

EXAMPLE 7 2,3,5,6-tetrachloro-pyrazine from 1,4-bis(2-hydr0xyethyl)piperazine 250 cc. of 1,2,4-trichlorobenzene are' added to 87 grams (0.5mol) of l,4-bis(2- hydroxyethyl)piperazine while cooled with ice and themixture is chlorinated for 6 hours at 25 C. under irradiation withultraviolet light. It is then heated and chlorination continued whilethe temperature is slowly raised to 200 C. Subsequently the reactionmixture is fractionated in vacuum. At boiling point 100140 C. 14 mm. Hga fraction is obtained from which tetrachloropyrazine crystallizes oncooling. Recrystallization from acetonitrile or methanol yieldscolorless flakes of melting point 96-99 C.

Analysis.C Cl N (molecular weight 2l7.9)-cal- Found: C, 22.40%, 22.42%;N, 12.65%, 12.66%.

EXAMPLE 8 Ietrachloropyridines-and pentachloro-pyridine from N-methyl-piperidine Chlorine is passed at 10 C. into a solution of 198grams (2 mols) of N-methyl-piperidine in 200 cc. of chloroform whilecooling with ice. A pasty suspension is obtained which is thenchlorinated at 20 C., while the mixture is stirred and irradiated withultraviolet light, until the solution becomes clear. The temperature isthen slowly raised, the chloroform distilled off at 60 C.,

The reaction and while chlorine is passed under further irradiation withultraviolet light the mixture is maintained for several hours each at120 C., 140 0, 160 C., 180 C. and finally at 200 C. Subsequentlynitrogen is blown through the mixture and it is fractionated in vacuum.At boiling point 109-125 C. at a pressure of 12mm. Hg, 234 gramstetrachloropyridine distils over. A fraction of boiling point 125-140 C.at a pressure of 12 mm. Hg, yields when cooled a solid precipitate of 31grams (=6.2% of the theoretical) of pentachloropyridine (from ethanol,colorless polyhedrons having a melting point of 125127 C.) and a motherliquor containing 22 grams of tetrachloropyridine. The total yield ofisomeric tetrachloropyridines amounts to 256 grams (59% of thetheoretical).

Analysis.C Cl N (molecular weight: 251.4)calculated: C, 23.89%; Cl,70.52%; N, 5.57%. Found: C, 24.04%, 24.20%; Cl, 70.45%, 70.65%; N,5.71%, 5.76%.

AnaIysis.C I-ICI N (molecular weight: 216.9): calculated: C, 27.69%; H,0.47%; N, 6.46%. Found: C, 27.20%, 27.46%; H, 0.5%, 0.5%; N, 6.41%.

EXAMPLE 9 366 parts by weight of dimethyl-aniline are chlorinated, firstwithout irradiation, at a temperature between 20- 60 C. until thereaction stops being exothermic (chlorination of the nucleus). From atemperature of 60 C. onwards, the chlorination is then continued underultraviolet irradiation. The temperature is raised in such a way that. atemperature rise of about C. per hour takes place. When the temperaturehas reached 190- 220 C., chlorination is continued for a further 3 hoursat this temperature. Nitrogen is then passed through in order to removeany dissolved chlorine.

During the subsequent vacuum-distillation trichlorophenylimidocarbonylchloride distils over at a pressure of 0.3 mm. ,Hg at 889'1 C.

Yield: 648 parts by Weight, n =1.5970

Analysis.C H NCl oalculated: C, 30.15%; H, 0.72%; N, 5.06%; CI, 64.2%.Found: C, 30.17%; H, 0.78%; N, 5.65%; Cl, 64.4%.

EXAMPLE 10 C1 distils over at-a boiling point of 1-26-128 c./12 mm. Hg.

Yield: 672 parts by weight, n :1.5751

Analysis.-C N Cl -calculated: C, 19.5%; N, 22.8%;

Cl, 57.6%. Found: C, 19.62%; N, 22.87%; Cl, 56.97%. The products areidentical with the so-called tetrameric cyanogen chloride which isformed in small quantities in the trimerization of cyanogen chlorideinto cyanuric chloride.

EXAMPLE 11 110 parts by weight of 2,4,-bis(dimethylamino)-6-chlorotriazine-1,3,5 are chlorinated as described in Example 10. Uponfractionating, there are obtained, after 8 first runnings of cyanuricchloride and trichloromethylimidocarbonyl chloride, 59 parts by weightof'the compound B.P. l06-112 C./0.07 mm. Hg; n 1.5854

Analysis.-C N5Cl calculated: C, 19.6%; N, 22.8%; C1, 57.9%. Found: C,19.94%; N, 22.57%; C1, 58.45%.

EXAMPLE 12 hoursat ZOO-230 C. Excess chlorine is then removed by blowingthrough nitrogen and pentachlorophenylirnidocarbonyl chloride having theforegoing formula is distilled off under high vacuum. It boils at apressure of 0.1 mm. Hg at 134-l38 C. and has a refractive indexAnalysis.C Cl-;N-calculated: C, 24.3%; N, 4.05%; Cl, 70.6%. Found: C,24.4%; N, 4.5%; CI, 71.5%.

EXAMPLE 1 3 232 grams of a compound having the formula 01 N=( JN(CHa)2C1 Cl that was obtained by condensation of trichlorophenylimidocarbonylchloride (Example 5) and dimethyl-amine [B.P. 128-131 C./0.09 mm. Hg]are chlorinated as described in Example 12. Excess chlorine is thenremoved by blowing through nitrogen and the reaction product distilledoff under a high vacuum. Boiling point 138- 142 C. at 0.1 mm. Hg; n=l.6080.

Analysis.C H Cl N calculated: C, 28.3%; H, 0.59%; N, 8.25%; Cl, 63.0%.'Found: C, 28.47%; H, 0.65%; N, 8.22%; Cl, 63.55%.

EXAMPLE 14 o1 N=C/ A mixture of 366 parts by weight of2-N,N-dimethylamino toluene and 300 parts by volume of chloroform ischlorinated as described in Example 12 and worked up.

9 The reaction product boil-s at a pressure of 0.05 mm. H at 130-136 C.;n =1.6107.

Analysis.C H Cl N--calculated: C, 29.4%; H, 0.92%; N, 4.3%; Cl, 65.4%.Found: C, 28.96%; H, 0.91%; N, 4.28%; Cl, 65.45%.

240 parts by weight of 2,5-dimethylamino-3,6-dichlorop-benzoquinone and1500 parts by volume of trichlorobenzene are chlorinated at roomtemperature under ultraviolet irradiation. Without external supply ofheat the temperature of the mixture rises to 80 C. After the exothermicreaction has subsided the mixture is further chlorinated as described inExample 9. The solvent is finally distilled off and a product having theforegoing formula is obtained in the form of pale yellow crystals havinga melting point of 264-266 C. (after recrystallization from xylene),besides a red oil of unknown constitution.

Analysis.C Cl N O calculated: 9.4%; Cl. 47.6%; 0, 10.7%. 9.3%; 01,46.7%; 0, 11.5%.

Hydrolyzable chlorine: Calculated: 23.8%. 23.5

c, 32.2%; N, Found: C, 32,7%; N,

Found EXAMPLE 16 while chlorine is continually introduced and then themixture kept at 220-230 C. for 20 hours. Hydrogen chloride and excesschlorine are then driven outwith nitrogen and the reaction mixture issubjected to fractional distillation in a silver-lined column.3-chloroform ylhexachloropropylimidocarbonyl chloride distils over at apressure of 15 mm. Hg at 188189 C. and forms a crystalline solid in thereceiver. By recrystallization from acetonitrile the product is obtainedin the form of colorless polyhedrons having a melting point of 98- 10lC.

Analysis.Molecular weight 409.2. Calculated for C Cl NO: C, 14.68%; Cl,77.99%; N, 3.42%; O, 3.91%. Found: C, 14.84%, 14.86%; Cl, 77.75%,77.90%; N, 3.63%, 3.63%; O, 4.11%, 4.31%.

We claim:

1. 'A process for the production of an organic compound containingchlorine and nitrogen combined in the N=CCl radical which comprises:

(A) reacting an amino compound selected from the group consisting of (i)amines of the formula lower alkyl, cyano-substituted lower alkyl,

phenyl-substituted lower alkyl, phenyl, chlorophenyl, cyano-phenyl,nitro-phenyl, naphthyl,

benzoquinonyl, chloro-substituted triazinyl, chloro andamino-substituted tn'azinyl,

B s-N wherein R is a member selected from the group consisting ofchloro-phenyl, lower chloro alkyl and phenyl, and R stands for a memberselected from the group consisting of chloro and amino, and

-R4N I wherein R is lower alkyl and R and R are separately lower alkyland when taken together with the nitrogen to which they are attached, a5 to 6 membered heterocyclic group containing nitrogen as the onlyheterocyclic atom, '(ii) salts of said amines with hydrogen halides, and(iii) quaternary salts of said amines with al'kyl halides, with chlorinewhile it is irradiated with ultraviolet light at a temperature below 140C. for such a period that replaceable hydrogen atoms and the aminocompound are replaced by chlorine atoms, (B) further treating thereaction mixture containing the chlorine-containing compound withadditional chlorine at a higher temperature between 140 C. and 300 C.while it is-irradiated with ultraviolet light, and (C) recovering theresulting organic compound containing nitrogen and chlorine combined inan N=CC1 radical. 2. A process for the production of an organic nitrogencompound containing chlorine and nitrogen combined in the N'=CCl radicalwhich comprises (A) reacting a compound selected from the groupconsisting of (i) amines of the formula R2 in which R and R stand foralkyl and in which R stands for a member selected from the groupconsisting of alkyl and aryl radicals and their halogen, cyano, aryl,alkyl, amino and imino derivatives, (ii) salts of said amines withhydrogen halides and (iii) quaternary salts of said amines with hydrogenhalides with chlorine at temperatures below 140 C. until all replaceablehydrogen atoms are replaced by chloro-atoms.

(l3) treating the chlorination product thus obtained with chlorine attemperatures between 140 and 300 C., whereby alkyl chloride is splitoff, and

(C) recovering the organic nitrogen compound from the reaction mixture.

3. A process for the production of ethylene-1,2-bis [imidocarbonylchloride] 'which comprises reacting 1,2

bis(dimethylarnino)ethane in solution in 1,2,4-trichlorobenzene withchlorine at a temperature between 70 and C. while it is irradiated withultraviolet light, con tinuing the reaction with chlorine at atemperature gradually increasing to 200 C. and thereafter at atemperature between 200 and 230 C., and subsequently recovering theethylene-1,2-bis [imidocarbonyl chloride] thus produced.

4. A process for the production of trichloromethylimidocarbonyl chloridewhich comprises reacting a suspension of trimethylamine hydrochloride in1,2,4-trichlorobenzene withchlorine at a temperature of approximately C.while it is irradiated with ultraviolet light, distilling off the1,2,4-trichlorobenzene and reacting the resulting mixture of chlorinatedamines with chlorine at a temperature between and 200 C. andsubsequently recovering the trichloromethylimidocarbonyl chloride.

5. A process for the production of pentachloroethylimidocarbonylchloride 'which comprises reacting a suspension of1-dimethylamino-2-chloroethane hydrochloride in 1,2,4-trichlorobenzenewith chlorine at a temperature between approximately 130 and 140 C.While it is irradiated with ultraviolet light, continuing the reactionwith chlorine at a temperature between 160 and 210 C.,

. and subsequently recovering the pentachloroethylimidocarbonylchloride.

6. A process for theproduction of trichlorophenylimidocarbonyl chloridewhich comprises reacting a suspension ofN-phenyl-N,N,N-trimethylammonium chloride in l,2,4.-trichlorobenzenewith chlorine at a temperature of approximately 100 C. while it isirradiated with ultraviolet light, continuing the reaction with chlorineT2 ultraviolet light and subsequently recovering thetrichlorophenylimidocarbonyl chloride thus produced.

8. A process for the production of pentachlorophenylimidocarbonylchloride which comprises reacting N,N-dimethylpentachloroaniline inchloroform with chlorine at a temperature between and C. While it isirradiated with ultraviolet light, distilling off the chloroform andcontinuing the reaction of the residue with chlorine at temperaturesgradually increasing to between 200 and 230 C., and subsequentlyrecovering the pentachlorophenylimidocarbonyl chloride.

References Cited by the Examiner JOHN D. RANDOLPH, Acting PrimaryExaminen DUVAL T. MCCUTCHEN, NICHOLAS S. RIZZO,

WALTER A. MODANCE, Examiners.

1. A PROCESS FOR THE PRODUCTION OF AN ORGANIC COMPOUND CONTAININGCHLORINE AND NITROGEN COMBINED IN THE -N=CCL- RADICAL WHICH COMPRISES:(A) REACTING AN AMINO COMPOUND SELECTED FROM THE GROUP CONSISTING OF (I)AMINES OF THE FORMULA
 2. A PROCESS FOR THE PRODUCTION OF AN ORGANICNITROGEN COMPOUND CONTAINING CHLORINE AND NITROGEN COMBINED IN THE-N=CCL- RADICAL WHICH COMPRISES (A) REACTING A COMPOUND SELECTED FROMTHE GROUP CONSISTING OF (I) AMINES OF THE FORMULA